In Keynote, choose Save As..., check the Save copy as checkbox, select iWork '08 as the format, and click OK.

However, doing this for each document is tedious. I'd like a way to convert them all at once.

I've been trying to create an Automator workflow for this, but have been completely unsuccessful. (I think being a programmer actually makes it impossible to understand the for-the-rest-of-us tools like Automator and AppleScript.) Can anyone help me out?

I can record the UI events (Open With, Save As, etc.). The problem is that this gives me a workflow that only works for a single selected document in the Finder. I want to run it for a large set of documents. How would I do that with Watch Me Do?
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Kristopher JohnsonFeb 18 '11 at 0:09

I couldn't figure out how to get Automator to do it, but I was able to beat AppleScript into submission. Just save the following as an Application in the AppleScript Editor, then drag the files you want to convert onto the icon. It will prompt you to choose a folder where the converted files will be placed.

on open droppedFiles
set theDestinationFolder to (choose folder with prompt "Choose destination folder") as Unicode text
repeat with theFile in droppedFiles
tell application "Keynote"
open theFile
set theSlideshow to slideshow 1
set theDestinationPath to theDestinationFolder & (name of theSlideshow)
save theSlideshow in theDestinationPath
close theSlideshow
end tell
end repeat
end open

(I don't really know what I'm doing with AppleScript. If there are improvements that can be made here, I'd like to know about them.)